Health Care Workers Cohort Study in the EuCARE Project (EuCARE-HCW)

September 15, 2025 updated by: Euresist Network GEIE
The WP3 healthcare workers cohort in EuCARE is an observational multicentre study including collection of retrospective (historical) and prospective data and sample collection from health care workers with either a vaccination or a confirmed SARS-CoV-2 infection. Samples from HCW are sent to central laboratories for WP2 study were the impact of different variants in humoral and cellular immunity is to be analysed by biostatistical methods and with artificial intelligence in WP5. This analysis will focus on the impact on vaccine escape of viral variants / viral sequences as well as on any escape from any combination of natural and vaccine induced immunity. Eight countries will participate (Portugal, Italy, Germany, Lithuania, Georgia, Russia, Vietnam and Mexico).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Background: Protection from SARS-CoV-2 infection is known to occur soon after vaccination or natural disease, fading over time. Although protection from serious illness does occur, protection from infection is insufficient and the impact of each variant and of each vaccine or vaccine schedule is a matter of continuous study. Recruiting participants from countries with different vaccines and vaccine schedules is of upmost importance to analyse these relationships and breakthrough infections. Study objectives: The EuCARE-HCW study contributes with data and samples from

HCW to EuCARE-IMMUNITY study that will analyse the NtAb and CMI to different SARS- CoV-2 variants following any combination of natural infection and vaccination. Specific

objectives include:

  • to collect data and biological material from COVID-19 healthcare workers in 9 clinics from 8 countries and 3 continents.
  • Enrolment of HCW with an immunogenic event, either vaccination or infection.
  • Periodic collection of serum and whole blood every 4 months since enrolment and during 12-24 months (depending on how long immunity persists).

  • Sample preparation, storage and shipment to central EuCARE laboratories where WP2 study group will analyse natural and artificial immunity to SARS-CoV-2 variants (EuCARE-IMMUNITY), namely:

    • Analyse the magnitude, breadth and duration of immunity following natural infection and/or vaccination.
    • Define the cross-immunity among the different viral variants.
    • Analyse the immune escape in a comprehensive set of combinations of vaccines and natural infection(s).

  • To accomplish the above objectives, WP2 will test:

    • Neutralising antibodies
    • Cellular immunity
    • Viral sequences

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
1800

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

For each subject baseline will be the occurrence of the first known immunization event, either natural infection or vaccination. The follow-up is planned to last 24 months with respect to this baseline.

Health CareWorkers can be enrolled in the category of:

(i) vaccination not followed by any later infection, (ii) infection followed by vaccination and (iii) vaccination followed by infection. However, infections diagnosed during the first wave of the epidemic are suitable for the analysis of natural immunity to SARS-CoV-2 because vaccination was administered several months later.

Description

Inclusion Criteria:

The study subjects will be selected based on the following inclusion criteria:

  1. Adult (>18 years) HCW with mandatory information on their SARS-CoV-2 infection and vaccination status.
  2. For those with a history of SARS-CoV-2 infection, diagnosis obtained by detection of SARS-CoV-2 RNA
  3. Having a signed informed consent when required by ethical approval

Exclusion Criteria: NONE

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Other

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Heath care workers (HCW)
Adult (>18 years) HCW with mandatory information on their SARS-CoV-2 infection and vaccination status. For those with a history of SARS-CoV-2 infection, diagnosis obtained by detection of SARS-CoV-2 RNA
Other: Follow up of the first known immunization event

The baseline for enrolment into the study is defined by the occurrence of the first known immunization event, either natural infection or vaccination. The follow-up is planned to last 24 months with respect to this baseline. In subjects with natural infection, the viral variant must be determined for each prospective case by analysis of a nasopharyngeal swab obtained as soon as possible at diagnosis. For historical cases where the variant was not determined and a contemporary nasopharyngeal swab has not been stored, the viral variant may be inferred when a specific variant was dominating the geographic area according to official records available at local health agencies. However, the variant assignment will be labelled as putative, rather than proved.

HCWs can be enrolled in the category of:

(i) vaccination not followed by any later infection, (ii) infection followed by vaccination and (iii) vaccination followed by infection.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of HCW involved in the study
Time Frame: through study completion, an average of 3 years
To collect the higher possible number of data and biological materials from the HCWs of the participating Units
through study completion, an average of 3 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Euresist Network GEIE

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Heinrich-Heine University, Duesseldorf
Centro Hospitalar Lisboa Ocidental
ASST Santi Paolo e Carlo
Bach Mai Hospital
Hospital Regional de Alta Especialidad "Dr. Juan Graham Casasus"
Vilnius University Hospital Santaros Klinikos
Istituto Europeo di Oncologia

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: CRISTINA TOSCANO, DR, Centro Hospitalar de Lisboa Ocidental (CHLO)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 15, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 15, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 6, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 6, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 9, 2022

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 19, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 15, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • EuCARE-HCW

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

The study is part of a project funded by the European Commission and the project agreement with theCommission affirms that the data and the results will be publi

IPD Sharing Time Frame

AFTER THE STUDY END NO TIME LIMIT WAS FIXED

IPD Sharing Access Criteria

REQUEST TO THE STUDY COORDINATOR OR TO THE PROJECTPARTNERS

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings